Field of the Invention
The present invention relates to an impregnated fiber tube for internally lining conduits, sewers, and pipes, a method of manufacturing the fiber tube, a method of rehabilitating conduits, sewers, and pipes, and use of the fiber tube for rehabilitating conduits, sewers, and pipes.
Description of Related Art
Up to now pipes have been rehabilitated such that a polymeric inner tubular foil has been arranged in a resin-impregnated glass fiber-reinforced tube (liner), which inner tubular foil has been erected by means of compressed air to press the resin-impregnated fiber tube against the pipe wall. In prior art, the resin has then been hardened either by UV radiation or by action of heat (steam, hot water or IR).
In the case of UV hardening a device is normally drawn through the tube erected by compressed air. Either during this process or before during mounting of packers the polymeric inner tubular foil may be easily damaged. A production error during manufacture of the inner tubular foil cannot be precluded either. Even small defects allow compressed air to enter the only partially hardened liner, which, when the liner is completely hardened, inevitably results in a leaky end product. In the case of major defects (e.g. a bursting foil) the entire product collapses and hardening is impossible. These problems encountered with prior art foils require the hardened and leaky liner to be painstakingly milled out, or in the case of a burst foil the collapsed liner to be drawn out of the reach and disposed of. Both cases result in a considerable economic loss.
WO 2010033297 A2 describes telescoped resin-impregnated fiber tubes or resin-impregnated fiber tubes arranged one on top of the other. At the inner surface a polymer tubular foil may be inserted. This polymeric inner tubular foil may have a thickness ranging between 0.1 and 1 mm. This tube may further be made of polyamide. The tube may be connected at its ends with the respective ends of the fiber tubes by sewing, for example. This is disadvantageous in that the foil is loosely inserted in the fiber tube and is thus susceptible to damage.
DE 19924251 A1 describes a foil tube where a layer of non-woven material is laminated to the polymer foil. This foil tube is placed around the outer surface of the actual lining tube. This outer foil tube constitutes an armoring adapted to protect against mechanical influences of the pipe inner wall to be rehabilitated. As in other prior art, the inner surface is provided with a polymeric inner tubular foil. This system thus has the same disadvantages as the prior art described above. This document further describes that this polymeric inner tubular foil can shift with respect to the lining tube. The lining tube described in this document is not invertible since it is made up of a wound glass fiber mat and would fall apart when being pushed into a pipe to be rehabilitated by an inversion process. Since this lining tube is made up of wound mats, neither an outer foil nor an inner tubular foil can be reliably connected with the impregnated fiber tube.
The present technology is described in ASTM F1216-09.
In prior art it has so far not been worked out how to configure the inner tubular foil such that it is less susceptible to damage and may remain in the liner after installation, which would result in an optimization of processes performed on site since removing and disposing of the inner tubular foil would be omitted.